Determining the life history strategy of the cryptobenthic reef gobies Coryphopterus hyalinus and C. personatus

Abstract

Understanding the life history strategy of species can clarify their functional role, and contribution to the productivity and resilience of an ecosystem. We use otolith microstructure analysis to study the life history of 2 widespread and abundant Caribbean reef fishes, genetically identified here as the glass goby Coryphopterus hyalinus and masked goby C. personatus. Our analysis reveals that these species exhibit an extreme life history relative to other vertebrates due to their short lifespan, small adult body size, early maturity, and continuous growth in body length throughout reproductive age. We find that pelagic larval duration (PLD) varies widely, and average larval growth influences PLD where faster-growing larvae have shorter PLDs. We show that average daily growth substantially decreases during the settlement transition to reef habitat, approximately coinciding with reproductive maturity. Continuous somatic growth throughout reproductive age can serve to support greater fecundity in older, larger-bodied females and enhance survivorship. Several features of the ecology (i.e. broad depth range, planktivorous diet) and life history (i.e. small adult body size, quick generational turnover, short lifespan) of C. hyalinus and C. personatus indicate that they play a key trophic role in transferring nutrients from pelagic plankton to Caribbean reef predators and the reef benthos. Our analyses highlight why life history traits related to survival, reproduction, and population dynamics can enhance our understanding of ecosystem-scale processes and functioning on coral reefs.